The present invention relates to an apparatus for the staining of biological slides, and particularly to a slide staining apparatus which may automatically process a plurality of such slides.
In the biological arts, and particularly in the field of medical technology, the investigation of living tissues and fluids for structure and possible pathology has long proceeded with the aid of microscopic investigation. Specifically, samples of tissues and fluids have classically been placed upon small rectangular glass plates, known as slides, which are then placed under a microscope or similar magnifying device where visible structural characteristics may be viewed. In connection with microscopic investigations, the employment of staining compositions developed to aid in the identification process. At the inception, slides were manually treated and stained prior to viewing, however, particularly in the area of medical technology, the great numbers of slides that required staining for viewing in critical disease investigations, made it clear that the manual staining technique was inadequate. To this end, those in the art sought to develop methods and associated apparatus for the automatic staining of a plurality of slides.
At present, apparatus for the automated multiple staining of slides is available which employs a conveyor-type transporting arrangement, whereby the slides are placed on the conveyor and are sequentially indexed past stations for the dispensing of stain composition, buffer, and then rinse solution. The type of device thus described is presently employed in the area of blood sample evaluation, where the aforementioned critical parameters of time and volume are most pronounced. Though serving to alleviate somewhat the difficulties encountered in the employment of manual staining of the blood samples, the machine thus described suffers from certain defects of operation. Specifically, the slide is locked in position with the conveyor upon placement thereon and cannot be removed from the machine if, for some reason, it is desired to manually treat the particular sample in question. Secondly, the slides are stained in serial order and, frequently suffer from non-uniform staining due to excess dispensing of the stain composition components at the respective stations. Further, the mechanism comprising the conveyor frequently causes jamming of slides with resulting delays in slide movement, which itself may contribute to overstaining of a particular sample, and which generally delays the staining process for all slides presently on the machine.
In addition to the above, the need has developed for the semi-automatic staining of a single slide, without resorting to fully manual staining techniques, so that the benefits of a premeasured amount of stain composition may be gained in conjunction with the ability to process a single slide. Presently, no device is known which possesses this latter capability, and, in sum, it is to the satisfaction of all of the foregoing deficiencies in the prior art that the present invention is directed.